Change fire perimter WMS query to check that results are updated and use cache if not

[jordan-evens]

Change code around:

https://cwfis.cfs.nrcan.gc.ca/geoserver/public/wms: 33.7MB [00:06, 5.64MB/s]
2026-07-16 16:13:21,641 -     INFO - [cwfis.py:69] - Reading /appl/data/runs/m3_202607161613/data/m3_polygons.json

to check latest update that would end up in m3_polygons.json and use cached version if not newer

[jordan-evens]

Worst case scenario you could query something like https://geoserver.cwfif.nrcan.gc.ca/geoserver/wfs?service=WFS&version=2.0.1&request=GetFeature&typename=public:cwfif_national_reportedfires&outputFormat=application/csv&SRSName=EPSG:3978&CQL_FILTER=record_start%3C%3Dnow%28%29%20and%20record_end%3Enow%28%29&propertyname=situation_report_date and parse the results for the max, but there has to be a way to just get max(situation_report_date)

[jordan-evens]

Maybe https://geoserver.cwfif.nrcan.gc.ca/geoserver/wfs?service=WFS&version=2.0.1&request=GetFeature&typename=public:cwfif_national_reportedfires&outputFormat=application/json&SRSName=EPSG:3978&CQL_FILTER=record_start%3C%3Dnow%28%29%20and%20record_end%3Enow%28%29&propertyname=situation_report_date&sortBy=situation_report_date+D&count=1